From the Guidelines
A bilirubin level of 15 mg/dL at 3 weeks of age is considered elevated and requires immediate medical evaluation, as it may indicate prolonged jaundice that needs investigation, and the infant should be seen by a healthcare provider right away for assessment and possible treatment with phototherapy, as recommended by the most recent guidelines 1.
Key Considerations
- The infant's bilirubin level is above the threshold for phototherapy, according to the guidelines, which recommend measuring total serum/plasma bilirubin (TSB) if the transcutaneous bilirubin (TcB) reading is ≥15 mg/dL 1.
- Blood tests will likely be ordered to determine the underlying cause of the elevated bilirubin level, such as breast milk jaundice, biliary atresia, hypothyroidism, or a metabolic disorder.
- Parents should not delay seeking care, as high bilirubin levels can lead to kernicterus, a form of brain damage, if left untreated, and the risk of bilirubin neurotoxicity can be reduced with phototherapy, as stated in the technical report 1.
Recommended Course of Action
- The infant should be seen by a healthcare provider right away for assessment and possible treatment with phototherapy.
- The healthcare provider will likely order blood tests to determine the underlying cause of the elevated bilirubin level.
- The infant should continue regular feeding to help eliminate bilirubin through bowel movements.
- The healthcare provider will monitor the infant's bilirubin level and adjust treatment as needed, according to the guidelines, which recommend intensive phototherapy at the thresholds based on gestational age, neurotoxicity risk factors, and age of the infant in hours 1.
From the Research
Bilirubin Levels in Infants
- A bilirubin level of 15 at age 3 weeks is considered high and may indicate hyperbilirubinemia 2, 3.
- Hyperbilirubinemia is a common condition in newborns, affecting 60% to 80% of all term infants, and is usually benign 2.
- However, high levels of bilirubin can increase the risk of developing bilirubin-induced neurologic dysfunction (BIND) if left untreated or undiagnosed 2, 3.
Risk Factors and Management
- The risk of developing BIND is dependent on two major processes: bilirubin production and elimination 2.
- An infant's genetic profile and bilirubin binding status can also affect their overall capacity to cope with the resultant tissue bilirubin load and affect risk 2.
- Nomograms can be used to plot total serum bilirubin levels and determine the need for phototherapy or exchange transfusion, taking into consideration hyperbilirubinemia and neurotoxicity risk factors 3.
Relationship between Bilirubin and Coagulation Test Results
- There is a significant positive correlation between bilirubin levels and prothrombin time (PT) and activated partial thromboplastin time (APTT) results in infants with prolonged jaundice 4.
- A higher bilirubin load to the liver may cause some degree of vitamin K deficiency due to mild cholestasis, but the importance of this finding and the possible benefits of vitamin K supplementation require further investigation 4.
Diagnostic Evaluation
- A complete blood count (CBC) with differential count and reticulocyte count can be a useful tool in diagnosing and interpreting blood disorders in infants, including those related to hyperbilirubinemia 5.